1. Field of the invention:
The present invention generally relates to electrical switches and specifically to push-button switches with internal rotary motion.
2. Prior Art
Switches which convert the linear motion of a push-button to the rotary motion of a switch are well-known in the art. These push-button switches are generally found on a multiplicity of appliances and are constructed primarily of metal components. The prior art has employed a brass spiral system which is coupled to a fiber disk as an internal component of the switch. The brass spiral stem engages the push-button in such a manner as to cause the spiral stem to rotate above its longitudinal axis as the push-button is depressed. Rotation of the spiral stem results in the coupled fiber disk causing the rotary movement of an abuting commutator. Rotation of the metallic commutator causes the wiping fingers attached to the commutator to make or break the electrical circuit connected to the push-button switch wires.
With the increased application of the push-button switch the new uses found may subject the push-button switch to conditions which are not the most ideal for its proper functioning. Under high humidity conditions the fiber disk of the prior art switch may not provide sufficient electrical isolation between the commutator and the user operated push-button. The aforedescribed situation may present a potential danger to the user under certain conditions, such as the aforementioned one of high humidity.
Additionally, the brass spiral stem operating with the conventional metal push-button must be prelubricated during switch assembly for proper operation of the push-button during its life. If for some reason the brass spiral stem is not prelubricated or the lubrication which has been provided gravitates to a nonworking area of the spiral stem, the push-button switch will have a shortened life. The lack of lubrication in the working area of the spiral stem causes excessive friction between moving parts with consequent wearing of the parts. Eventually binding of the push-button switch occurs and replacement is required.